Project KING (Tow)
Client required BLD to perform a deep-water leak detection survey at two active leachate ponds using the towed-probe survey method. The ponds were approximately 1.5 acres each and have been active for a minimum of 20 years. Due to the ponds being single-lined with an HDPE 80-mil geomembrane system, a 2-ft wide isolation trench was required for each pond. It is crucial for systems that are single-lined to have an electrical isolation perimeter or trench throughout the entire cell, if feasible. An electrical isolation trench consists of an area of exposed liner that divides the earth ground material and the matter in the cell covering the liner (in this case, the pond liquid).
Leachate Pond with Aerators
A 2-ft wide isolation trench was required Exposed geomembrane required
for this single-lined cell pond for electrical isolation in the cell
Since the electrical ground was connected to the aerators, removal of this was necessary to electrically isolate any conductive objects that will mask a leak. This included conductive cables and anchors.
Removing the ground sources were necessary to increase leak
detection sensitivity and prevent masking of actual leak signals
A total of three anomalies were found using the towed-probe survey method. Client will drain the ponds with further investigation of these anomalies at a later date.